Blanket cylinder moving mechanism for offset lithographic printing machines



July 13, 1954 c. G. KING BLANKET CYLINDER MOVING MECHANISM FOR OFFSET LITHOGRAPHIC PRINTING MACHINES 2 Sheets-Sheet 1 Filed Nov. 4, 1952 FIG. I.

card GusTfiuE KmG- July 13, 1954 c. G. KING BLANKET CYLINDER MOVING MEZCHANISMYFOR OFFSET LITHOGRAPHIC PRINTING MACHINES 2 Sheets-Sheet 2 Filed Nov. 4, 1952 (Lard G'USTAUE Kmcr Patented July 13, 1954 2,683,411 BLANKET CYLINDER MOVING MECHANISM FOR OFFSET LITHOGRAPHIC MACHINES Carl Gustave King, Kenton,

Rotaprint Limited, London,

comp any PRINTING England, assignor to England, a British Application November 4, 1952, Serial No. 318,665

Claims priority, application Great Britain November 9, 1951 11 Claims.

This invention relates to improvements in and relating to offset lithographic printing machines.

More particularly the invention relates to machine of the kind having a form cylinder, a blanket cylinder and an impression cylinder, wherein the blanket cylinder is rotatably mounted on a shaft having eccentric end portions adapted to be rotated relative to the machine frame on which they are mounted to vary the position of the blanket cylinder and move it into contact with the impression cylinder, the blanket cylinder being drawn into its final position by link means connected for rotation with the blanket cylinder and carrying a member adapted to engage an abutment fixed relatively to the said cylinder and which serves to determine the final printing position of the cylinder.

The abutment usually comprises two adjacent concave surfaces adapted to be engaged by a roller on one end of an arm forming part of the link means. In the known construction, it is the usual practice, at the start of printing, for the arm to be moved directly by hand to position the roller initially in contact with the first of the concave surfaces whereby the blanket cylinder is moved into engagement with the form cylinder, corresponding to blanket inking position, but is still spaced from the impression cylinder, the link means being carried round with the blanket cylinder as the latter rotates, whereby the roller will move over the first concave surface and engage the second of these surfaces to effect the movement of the said blanket cylinder into engagement with the impression cylinder.

The initial manual operation of the link means has several disadvantages in practice and it is an object of the invention to provide improved means for automatically effecting this initial movement.

According to the present invention an offset lithographic printing machine of the kind referred to is provided with means for detachably coupling the link means to the blanket cylinder, whereby as the latter rotates the link means is automatically rotated to make initial engagement with the abutment which-serves to determine the position of the said cylinder relative to the form and impression cylinders.

The link means may be provided with a coupling member adapted to be detachably connected with the blanket cylinder. Means is also provided for automatically disengaging the coupling member from the cylinder when the latter has rotated to a position wherein the link means is in engagement with said abutment.

To enable the invention to be fully understood it will now be described with reference to the accompanying drawings, in which:

Fig. 1 represents in diagrammatic form the cylinders of an oifset printing machine provided with link means and a coupling member according to one embodiment of the invention, in inoperative position, and

Fig. 2 is a similar view but showing the blanket cylinder rotated to a position wherein the link means is in initial engagement with the cylinder.

As shown in the accompanying drawings l' represents the form cylinder of the machine, 2 the blanket cylinder and 3 the impression cylinder. The blanket cylinder is rotatably mounted on a shaft having eccentric end portions 4 which are mounted in the frame of the printing machine, the eccentric end portions being identical whereby when they are rotated the cylinder 2 is moved as hereinafter described, into engagement with the form and impression cylinders.

The eccentric shaft portion 3 at one end of the cylinder carries a supporting member 5 having a' pair of links 6, I pivoted thereto, the links being connected by a cross-link 8 pivoted to their outer ends. An arm 9 is secured to the link 6 and car ries a roller Ill.

A bracket member H is mounted on an adjacent portion of the machine frame which is fixed includes a nose having a hook or like portion l6 and a tail IT. The blanket cylinder is provided with a cam like projection I8, the end it of which forms a shoulder adapted to be engaged by the nose IS. The coupling lever i5 is adapted to be moved into engagement with the projection is abut-' ment which determines the position of the said by a manually actuated push rod 26 having an arm 2! pivoted to its lower end, the said arm being connected with a pivoted lever 22.

Before the start of printing the parts of the machine will be in the position shown in Fig. l, the link means being held in inoperative position by the spring 23 and the coupling link le being disengaged from the projection It. hen the machine is ready for printing the rollers are set in motion and the push rod 29 depressed. This effects a pivotal movement of the arm 2i the lever 22 causing the free end of the latter to engage a projecting stud H on the tail 5 i of the coupling lever whereby the latter is pivoted in an anti-clockwise direction to move it nose portion 16 inwardly of the blanket cylinder to position the hook for engagement by the end IQ of the projection it. Accordingly as the ,t cylinder 2 rotates, the said projection will engage the coupling lever with the result that the latter and the link means to which it is attached will be carried round with the said cylinder. After a predetermined rotation of the cylinder, the roller on the arm 9 will initially engage the first of the arcuate abutment surfaces it, and at this moment the tail ll of the coupling member will strike a stop 24 whereby said member will be pivoted in a clockwise direction to disengage the hook [6 from the end face of the projection 253. As soon as the roller IQ is in engagement with the arcuate surface i3 the action of the spring 23 on the link means will tend to rotate the latter in a oounter-clockwise direction to cause the roller to ride on to the second arcuate surface is. The eccentric shaft portion 4, being connected with the link means is also rotated in a count rclockwise direction and the arcuate surface is accordingly determines the final printing position of the offset cylinder and when the roller on the link means engages this surface i l, the blanket cylinder will have been moved, by virtue of its mounting on the eccentric shaft portions, to a position to make the desired contact with the form and impression cylinders.

It will be noted that with the arrangement according to the present invention, the roller ill on the arm 9 is moved by the rotating cylinder into operative engagement with the arcuate abutment surfaces !3, I4, instead of having to be moved into this position by a manually lifted lever. In the present arrangement it is only necessary to depress the push rod 20 to pivot the coupling lever l and this requires considerably less effort than the actuation of the manually lifted lever in the prior arrangement referred to.

The push rod may be so arranged that it has to be held down until the coupling member is picked up by the projection 18 on the blanket cylinder.

The arrangement according to the present invention has the advantage that the push rod or the like which operates the coupling member can be mounted on any suitable part of the machine so that it is readily accessible both from the front and back of the machine to enable the link means to be operated by remote control. This is an important advantage over the prior arrangement referred to wherein the manually actuated lever could only be mounted on the blanket cylinder and accordingly was only accessible from the delivery side of the machine. Further the lever in the prior machine could be raised by operator at any time during the operational cycle of the machine, but with the present invention the movement of the cylinders is effected at precisely the correct time in the cycle of operations to produce the desired result.

If desired the concave stop means may be adjustable as described in co-pending U. S. application No. 296,006, filed June 27, 1952, now U. S. Patent No. 2,667,120.

I claim:

1. offset printing machine including form, impression, and blanket cylinders, a shaft on which said blanket cylinder is freely rotatable, an eccentric portion at each end of said shaft, bearing means for said eccentric shaft portions, for rotating eccentric shaft portions to move the blanket cylinder into printing engagement with said form and impression cylinders comprising a support mounted on one of said eccentric shaft portions, link means pivoted to said support. an arm carried by said link means, abutment means engageable by said arm, means for automatically coupling said support to said blanket cylinder on rotation of the later whereby said support is rotated to position the said arm in engagement with said abutment means, trip means for releasing said coupling means when said arm is in engagement with said abut; ent means and means operative on release of said coupling means to further rotate said support and effect a corresponding rotation of said eccentric shaft portions to cause the blanket cylinder to be moved into engagement with the form and impression cylinders.

2. An ofiset printing machine including form, impression, and blanket cylinders, a shaft on which said blanket cylinder is freely rotatable, an eccentric portion at each end of said shaft, bearing means for said eccentric shaft portions, means for rotating said eccentric shaft portions to move the blanket cylinder into printing engagement with said form and impression cylinders comprising a support mounted on one of said eccentric shaft portions, link means pivoted to said support, an arm carried by said link means, abutment means engageable by said arm, means for automatically coupling said support to said blanket cylinder on rotation of the latter whercby said support is rotated to position the said arm in engagement with said abutment means, trip means for releasing said coupling means when said arm is in engagement with said abutment means and spring means connected with said link means and operable on release of said coupling means to further rotate said support and move said arm over said abutment means and effect a corresponding rotation of said eccentric shaft portions to cause the blanket cylinder to be moved into engagement with the form and impression cylinders.

3. An olfset printing machine including form, impression, and blanket cylinders, a shaft on which said blanket cylinder is freely rotatable. an eccentric portion at each end of said shaft, bearing means for said eccentric shaft portions, means for rotating said eccentric shaft portions to move the blanket cylinder into printing engagement with said form and impression cylinders comprisinga support mounted on one of said eccentric shaft portions, link means pivoted to said support, an arm carried by said link means, abutment means engageable by said arm. means for coupling said support to said blanket cylinder, manually operable means for moving said coupling means into a position for effecting the automatic coupling of said support and blanket cylinder on rotation of the latter whereby 5, said support is rotated to position the said arm in engagement with said abutment means, trip means for releasing said coupling means when said arm is in engagement with said abutment means and means operable on release of said coupling means to further rotate said support and effect a corresponding rotation of said eccentric shaft portions to cause the blanket cylinder to be moved into engagement with the form and impression cylinders.

4. An offset printing machine as claimed in claim 3 wherein said manually operable means comprises a push rod, lever means pivoted to said push rod, and engageable with said coupling means on actuation of said push rod.

5. An offset printing machine including form, impression, and blanket cylinders, a shaft on which said blanket cylinder is freely rotatable. an eccentric portion at each end of said shaft. bearing means for said eccentric shaft portions, means for rotating said eccentric shaft portions to move the blanket cylinder into printing engagement with said form and impression cylinders comprising a support mounted on one of said eccentric shaft portions, link means pivoted to said support, an arm carried by said link means, abutment means engageable by said arm, a pivoted latch carried by said support, a latch engaging member carried by said blanket cylinder, manually operable means for moving said latch into a position for automatic engagement with said member to couple said support to said blanket cylinder on rotation of the latter, whereby said support is rotated to position the said arm in engagement with said abutment means, trip means for releasing said latch when said arm is in engagement with said abutment means and means operable on release of said latch to further rotate said support and eifect a corresponding rotation of said eccentric shaft portions to cause the blanket cylinder to be moved into engagement with the form and impression cylinders.

6. An offset printing machine as claimed in claim 5 wherein said manually actuated means comprises lever means engageable with said latch to pivot it into position for engagement by said latch engaging member carried by the blanket cylinder.

'7. An offset printing machine as claimed in claim 5 wherein said manually actuated member comprises a push rod, and lever means pivoted to said push rod and engageable with said latch to pivot it into position for engagement with said latch engaging member.

8. An offset printing machine including form, impression, and blanket cylinders, a shaft on which said blanket cylinder is freely rotatable, an eccentric portion at each end of said shaft, bearing means for said eccentric shaft portions, means for rotating said eccentric shaft portions to move the blanket cylinder into printing engagement with said form and impression cylinders comprising a support mounted on one of said eccentric shaft portions, a pair of links pivoted to said support, a cross link pivoted to said pair of links at points spaced from their pivotal connection with the support, an arm carried by one link of said pair, abutment means engageable by said arm, means for automatically coupling said support to said blanket cylinder on rotation of the latter whereby said support is rotated to position the said arm in engagement with said abutment means, trip means for releasing said coupling means when said arm is in engagement with said abutment means and means operable on release of said coupling means to further rotate said support and effect a corresponding rotation of said eccentric shaft portions to cause the blanket cylinder to be moved into engagement with the form and impression cylinders.

9. An offset printing machine including form, impression, and blanket cylinders, a shaft on which said blanket cylinder is freely rotatable, an eccentric portion at each end of said shaft, bearing means for said eccentric shaft portions, means for rotating said eccentric shaft portions to move the blanket cylinder into printing engagement with said form and impression cylinders comprising a support mounted on one of said eccentric shaft portions, a pair of links pivoted to said support, a cross link pivoted to said pair of links at points spaced from their pivotal connection with the support, an arm carried by one link of said pair, abutment means engageable by said arm, means for automatically coupling said support to said blanket cylinder on rotation of the latter whereby said support is rotated to position the said arm in engagement with said abutment means, trip means for releasing said coupling means when said arm is in engagement with said abutment means, and spring means connected with one of said pair of links and operable on release of said coupling means to further rotate said support and effect a corresponding rotation of said eccentric shaft portions to cause the blanket cylinder to be moved into engagement with the form and impression cylinders.

10. An offset printing machine including a machine frame, form, impression, and blanket cylinders, rotatably mounted in said frame, a shaft on which said blanket cylinder is freely rotatable, an eccentric portion at each end of said shaft, bearing means in said frame for said eccentric shaft portions, means for rotating said eccentric shaft portions to move the blanket cylinder into printing engagement with said form and impression cylinders comprising a support mounted on one of said eccentric shaft portions, link means pivoted to said support, an arm carried by said link means, a roller mounted on said arm, abutment means fixed on said frame and engageable by said roller, means for automatically coupling said support to said blanket cylinder 0n rotation of the latter whereby said support is rotated to position the said roller in en.- gagement with said abutment means, trip means for releasing said coupling means when the blanket cylinder and support have been rotated to position said roller in engagement with said abutment means and spring means connecting said linkmeans to said frame and operable on release of said coupling means to further rotate said support and effect a corresponding rotation of said eccentric shaft portions to cause the blanket cylinder to be moved into engagement with the form and impression cylinders.

11. An offset printing machine including form, impression and blanket cylinders, a shaft on which said blanket cylinder is freely rotatable, an eccentric portion at each end of said shaft, bearing means for said eccentric shaft portions, means for rotating said eccentric shaft portions to move the blanket cylinder into printing engagement with said form and impression cylinders comprising a support mounted on one of said eccentric shaft portions, link means pivoted to said support, an arm carried by said link means, abutment means engageable by said arm, means for coupling said support to said blanket cylinder, manually operable means for moving said coupling means into a position for effecting automatic coupling of said support and said blanket cylinder on rotation of the latter whereby said support is rotated to position the said arm in engagement with said abutment means, trip means for releasing said coupling means when said arm is in engagement with said abutment means and spring means connected with said link means and operable on release of said coupling means to further rotate said support 8i and move said arm over said abutment means to effect a corresponding rotation of said eccentric shaft portion to cause the blanket cylinder to be moved into printing engagement with the form and impression cylinders.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 913,119 Ford Feb. 23, 1909 2,547,470 Janke Apr. 3, 1951 2,568,761 Peyrebrune Sept. 25, 1951 2,578,700 Harroldet a1 Dec. 18, 1951 

